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<A NAME="pgfId-194375"></A>TOPIC_DATA</H4>
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<A NAME="pgfId-194387"></A>The <A NAME="marker-249691"></A>TOPIC_DATA policy applies to <A NAME="marker-268211"></A>topic entities via the <EM CLASS="Code">
topic_data</EM>
 member of TopicQoS structures. Below is the IDL related to the topic data QoS policy:</LI>
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<A NAME="pgfId-194410"></A><EM CLASS="Code">
</EM>
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<A NAME="pgfId-194460"></A><EM CLASS="Code">
struct TopicDataQosPolicy {</EM>
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<A NAME="pgfId-194411"></A><EM CLASS="Code">
  sequence&lt;octet&gt; value;</EM>
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<A NAME="pgfId-194412"></A><EM CLASS="Code">
};</EM>
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<A NAME="pgfId-194388"></A><EM CLASS="Code">
</EM>
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<A NAME="pgfId-268358"></A>By default, the <EM CLASS="Code">
value</EM>
 is not set. It can be set to attach additional information to the created <A NAME="marker-268361"></A>topic. The value of the TOPIC_DATA policy is available in <A NAME="marker-268370"></A>data writer, <A NAME="marker-268375"></A>data reader, and <A NAME="marker-268380"></A>topic <A NAME="marker-268394"></A>built-in topic data. The remote application can obtain the information via the built-in topic and use it in an application-defined way.</LI>
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